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Author Topic: SRD - Penthouse or Basement - preference? Mark Gulbrandsen Resident Trollmaster Posts: 16657 From: Music City Registered: Jun 99 posted 04-17-2005 09:28 AM                     quote: Steve Guttag I'll put my basements up against your penthouses...they will track any film your penthouses will. Steve, The main problem I have with basement stuff is that installing it in the optical soundhead will yield more inconsistent results overall because the optical soundhead itself is more likely to need regular attention to keep the digital working at its best, particuluarly 5 star and SH1000 type. Century is less maintainance generally, but the projector heads more than make up for that. As I mentioned there is a place in the buisness for basement type stuff but its not a really good thing for theatres that do not get "normal maintainance" on a regular basis or decent prints. About half the 400 or so screens we service get what I would call normal maintainance so I think you can see why I feel the way I do. In my experience even twice yearly is not enough tweeking for reliable operation of the older basement stuff. Sure they all work but there are far more critical variables having it down there. Penthouses for the most part stay working with little to no maintainance while optical soundheads don't stay working properly with out some occasionnal maintainance. Although I think you'd find yourself in a minority I'm glad that yours work out so well, but out here they just don't while the penthouses always keep on chugging along. The fact is that there are less variables that can be affected by lack of service on penthouses in general. There is alot of dust problem out west that you don't have back east and that is another contributing factor towards unreliable basement results for the most part. Many theatres here, even first run, have trouble getting decent SRD tracks on brand new prints let alone on second run and indeed many second run theatres get prints that have damage that even penthouse readers have a hard time with let alone a basement... even your basement readers would not read them and many times there are no extra prints to get. So perhaps you can understand whay we've stuck with what works reliably for us out here. Louis, Out of round gear..... now why don't you replace them dude? They can and will run really nice. Actually I've measured pretty low W&F specs on SH-1000s in the past. They generally average around .1 to .15% which is pretty decent and as good as many 35mm mag dubbers. Those out of round gears will certainly affect analog playback!! The Century direct drive JJ always measured higher than the 35mm Centurys, with the movement pulled it measured as good. I never saw much W&F difference between standard or direct drive except when a Bodine sync motor was used on DD, then it was consistantly higher because of hunting between poles. Three phase electronic drive always measured the lowest when set up on any Century. Also, the use of ABEC 7 bearings in any SH-100 type or Century sound head helps tremendously on the W&F specs!! The lowest W&F I ever measured on an optical repeoducer was on the Kalee 21 projector at .07% which is about the residual in the SMPTE film. Mark  |  IP: Logged Louis Bornwasser Film God Posts: 4441 From: prospect ky usa Registered: Mar 2005 posted 04-17-2005 10:07 AM                        Mark: Of course you are right about out-of-round gears. Several years ago we did our W&F readings and found about 9 of 10 Simplex large metal gears to be not round. At the time, there was no source to get better ones so we either filed the existing ones or, if minimal, just overlooked the problem since Digital worked OK. On the Centurys, there are 2 main imediments to low W&F. On standard drive the projector belt idler pulley in on the wrong side of the belt which causes acceration/deceleration of the projector when the back-side lump passes it by....Simplexx 5 star got that one right! Maybe I should make an adapter.. Using direct drive JJ vs. 35mm direct drive, some significant improvement is possible by using the JJ large flywheel. It is, unfortunately, hard to permanently change this due to doors being made differently. I have considered making a special Century flywheel with the mass of the JJ, but with a profile that puts the weight on the side near the operating side. This also improves gear "bounce" and the problem with shutter oscillation.  |  IP: Logged Mark Gulbrandsen Resident Trollmaster Posts: 16657 From: Music City Registered: Jun 99 posted 04-17-2005 10:19 AM                     Louis, Have you tried any of the 3 phase solid state drive motors? These motors will yield better results and they run alot smoother too. One of these motors may just eliminate your need for that larger JJ flywheel. I've used Baldor, Reliance, and several others but prefer the Baldor. The drive is alot more user friendly than the others and the motor is heavier too. Its also nice to take advantage of the jog feature to run the film down for those that have to do that. The jog feature is actually as easy on the gear train as turning the projector over by hand . Wolk, LaVezzi, and others can actually manufacture gears for you that are very tight tolerance in small batches for a fairly reasopnable price. Its less expensive to have your own made than it is to get em from Strong..... that is if you don't mind keeping some on the shelf. There were a lot of 1000's that had those goofy out of round gears and when they ran they made a funny whirring noise, easy to find em. We recently had LaVezzi run us a batch of 35mm only VKF holdback and intermittent sprockets for the DP-70. Wolk made us gate bands. So we can now maintain all the DP-70's out here for many years and for a song compared to what Kinoton wants for the parts, 480.00 alone for a 35mm intermittent sprocket. The VKF's will in all likelyhood be the last set of sprockets any of these projectors ever get. Mark  |  IP: Logged Steve Guttag We forgot the crackers Gromit!!! Posts: 12814 From: Annapolis, MD Registered: Dec 1999 posted 04-17-2005 03:51 PM                     Watch out on those cheaper motor controllers...we had a reliance controller that wasn't too accurate on its frequency output. It said 60H but the film speed was over 25fps...a fudge factor was needed! We've had great luck with TB Woods controllers...especailly the micro-drives. The Etracs are okay and a little less. Tell the controllers that at 60Hz your motor is turning at 2400rpm and you whola, you have an FPS read out to two decimal places.  |  IP: Logged Mike Babb Master Film Handler Posts: 250 From: Norwich UK Registered: Jul 2002 posted 04-17-2005 04:28 PM                        Thanks, and I also usually align lateral to the analog with the thought that it would be less tolerant of shifting than the digital, but probably both would be within acceptable range and I can't point to any problem doing it the other way. The analog lateral is also harder to bump "after the fact". Also my test film, I believe Dolby calls it cat 530 is measured at -2 azimuth, +1.72 lateral so one would hope they have enough margin built in, knowing that a printed Dolby tone loop is off that much.  |  IP: Logged Gordon McLeod Film God Posts: 9532 From: Toronto Ontario Canada Registered: Jun 99 posted 04-17-2005 05:04 PM                     I have had good luck with Baldor controllers  |  IP: Logged Mark Gulbrandsen Resident Trollmaster Posts: 16657 From: Music City Registered: Jun 99 posted 04-17-2005 09:15 PM                     quote: It said 60H but the film speed was over 25fps...a fudge factor was needed! There are two reasons for that happenning. 1. Motors, even these motors will run slightly fast with small loads that are under their rated load. Remember these motors generally run at the stated speed at full load. 2. There is nothing to tell the controller how fast the motor is going. There are feedback tachometers and controlers like the Baldor will take them and give you a precise feedback control for precise speed at all loads. I've also found that the Baldors run a wee bit off speed with out a tach controller. I prefer not to use them though and just set the speed with an optical tachometer instead. For running the DP-70's I have to set the controller to 49.11 hz instead of 50 hz. There is also still some speed drift with out a feedback loop but it is far less than a standard AC sync motor. Mark  |  IP: Logged Steve Guttag We forgot the crackers Gromit!!! Posts: 12814 From: Annapolis, MD Registered: Dec 1999 posted 04-17-2005 09:44 PM                     Actually, we were using the Relianace controller on an ELMO LX-1100 with a bodine 3-phase motor...the motor and controller were of the proper rating. It was the controller...only that controller had the problem (we didn't use it on the next machine)...we measured the frequency too...the Relianace was simply wrong but it was cheap...and again.. with a fudge factor and going down to 1/10 of a frame per second accuracy, we had a usable system. We just normally get 1/100 of a frame per second accuracy. Steve  |  IP: Logged Mark Gulbrandsen Resident Trollmaster Posts: 16657 From: Music City Registered: Jun 99 posted 04-17-2005 10:10 PM                     I only used Reliance stuff once on a pair of Dailies projectors. It was for fast forword capability but I don't remember any speed problems at 24. Have not used the Woods as its not too common around here. We have an actual Baldor stocking office about a mile from the shop so I tend to stick with them. Their controler is very user friendly and extremely versatile. With the feedback loop you could be to about 1/1000 of a frame if need be, however it is alot of extra expense for the tach as the unit does 1/100th as standard. I suspect its very similar to the Woods. Mark  |  IP: Logged Frank Angel Film God Posts: 5305 From: Brooklyn NY USA Registered: Dec 1999 posted 04-18-2005 11:12 AM                        This is getting WAY off topic guys & it;s my fault....so let's continue here: How to do 3D Interlock. Selsyns the way to go? It is sounding like these things are run just for speed control, but what about interlock....  |  IP: Logged

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